Oven door window unit for self-cleaning ovens

ABSTRACT

A window unit for a door of a self-cleaning oven has three transparent panes of glass clamped in spaced relation to provide a self-contained unit to be mounted in the window opening of an oven door. The middle pane of glass is elevated by thermostatic means at oven cleaning temperatures, and strips of heat reflecting material on the middle and outer panes of glass permit viewing into the oven at temperatures within the cooking range and are arranged to reflect heat as well as block visibility at oven cleaning temperatures.

United States Patent Katona et a1.

[54] OVEN DOOR WINDOW UNIT FOR SELF-CLEANING QVENS [72] Inventors: Joseph W. Katona, Walled Lake; David W. Crouse, Union Lake, both of Mich.

[73] Assignee: Mills Products, inc., Farmington, Mich.

[22] Filed: Mar. 18, 1971 [21] Appl. No.: 125,557

[52] US. Cl ..l26/200 [51] Int. Cl .F23m 7/00 [58] Field of Search 126/200 [56] References Cited UNITED STATES PATENTS 3,451,389 6/1969 Huff ..l26/200 [451 May 30, 1972 Primary Examiner-Carroll B. Dority, .lr. Attorney-Whittemore, Hulber & Belknap [57] ABSTRACT A window unit for a door of a self-cleaning oven has three transparent panes of glass clamped in spaced relation to provide a self-contained unit to be mounted in the window opening of an oven door. The middle pane of glass is elevated by thermostatic means at oven cleaning temperatures, and strips of heat reflecting material on the middle and outer panes of glass permit viewing into the oven at temperatures within the cooking range and are arranged to reflect heat as well as block visibility at oven cleaning temperatures.

8 Claims, 4 Drawing Figures s I '5 I 1 l I Patented May 30, 1972 3,665,915

INVENTORS.

OVEN DOOR WINDOW UNIT FOR SELF-CLEANING OVENS This invention relates to window units for self-cleaning ovens and particularly to a self-contained window unit having automatically operable means to provide a heat reflecting shield when the oven is operated at elevated cleaning temperatures. The unit consists of three panes of glass with the middle pane being supported on bimetallic strips which automatically elevate the middle pane a slight distance at temperatures above the normal cooking range. The inner surface of the outer glass and the outer surface of the middle pane of glass have strips of heat reflecting material thereon arranged in a pattern such that viewing into the oven is permitted through the spaces between the strips at temperatures up to the maximum cooking temperature. Elevation of the middle glass by the bimetallic actuator arranges the strips in staggered relation to form a shield for reflecting the heat back into the oven and for blocking visibility into the oven. Sprint strips at the top edge of the middle pane of glass insure return of the glass to its lower position when the cleaning cycle is completed.

In the drawings:

FIG. 1 is a fragmentary perspective view of a window unit embodying the invention;

FIG. 2 is a fragmentary vertical sectional view illustrating the relationship of the heat reflecting strips in the closed or elevated position of the middle pane of glass;

FIG. 3 is a fragmentary sectional view taken on line 3-3 of FIG. 2 and showing the window unit mounted in an oven door; and

FIG. 4 is a fragmentary sectional view showingthe heat reflecting strips positioned for viewing into the oven.

The window unit comprises an inner pane of glass 10, an outer pane 12, both of which are stationary, and a third or middle pane of glass 14 which is vertically movable relative to the panes l and 12. The inner plane and the movable pane 14 are separated by a continuous channel-shaped spacer 16 having its side edges 18 engaging the peripheral opposing edges of the panes l0 and 14. The outer glass pane 12 is maintained in spaced relation to the middle pane 14 by spacers 20 which may consist of small channel-shaped pieces disposed at each of the four comers of the window unit.

A clamping frame 22 surrounds the peripheral edges of the glass panels and maintains the .same in spaced relation as shown in FIG. 3. A liner 24 consisting of a strip of asbestos or other suitable material is disposed between the clamping frame 22 and the edges of the glass panels. The outer side edge 26 of the clamping frame 22 is adapted to clamp a continuous strip of trim molding 28 against the outer surface of the outer glass panel 12 and the inner side 30 of the clamping frame 22 is adapted to clamp a similar metal strip 32 against the inner surface of the inner glass panel 10. The strip 32 and the outwardly turned flange 34 on the side 30 of the clamping frame are adapted to support a sealing member 36 which may be made of asbestos or other suitable material which is adapted to be engaged by the laterally projecting flange 38 on the inner panel 40 of the oven door. A front door panel 42 also has a laterally directed flange 44, and the molding strips 28 and 32 cooperate with the door flanges 38 and 44 to properly locate the window unit within the oven door. The unit may be fastened to the door in any conventional manner.

The outer glass pane 12 has a series of strips 50 of heat reflecting material secured on its inner surface. The strips 50 may comprise gold foil or any other heat reflecting material and are arranged to extend horizontally across the pane 12in spaced relations. The middle glass pane 14 also has a series of strips 52 of heat reflecting foil or other material on its outer surface. The width of the heat reflecting strips 50 and 52 is equal to or slightly greater than the spacing between the strips.

The middle pane of glass 14 is vertically movable relative to the outer pane 12 by means of two or more bimetallic strips 54 which are confined between the bottom edge of the pane 14 and the clamping frame 22. Leaf springs 56 are confined between the upper edge of the pane l4 and the clamping frame and preferably one of the springs 56 is arranged opposite each of the bimetal strips 54.

When the oven is cold or operated through the normal cooking range, the bimetal strips 54 will remain relatively flat and the pane 14 will be inits lower position and maintained in such position by the leaf springs 56. In this position the strips 52 on the pane 14 are in horizontal alignment with the strips 50 on the pane 12 as shown in FIG. 4 so that viewing into the oven is permitted through the spaces between the strips. When the oven temperature is elevated above the normal cooking range during the cleaning cycle, the bimetal strips 54 will warp and elevate the glass pane 14 against the force of the springs 56 to the position shown in FIGS. 2 and 3. In this elevated position of the pane 14 the strips 52 are arranged opposite the spaces between the strips 50 on the pane 12, and the series of strips 50 and 52 thus cooperate to reflect all heat back into the oven and in effect form a solid heat reflective shield throughout the entire area of the window unit. When the cleaning cycle is completed and the oven temperature drops sufficiently, the bimetal strips will return to their normal flat position and the leaf springs 56 insure that the pane 14 is returned to its lower position in which viewing into the oven is permitted.

What we claim as our invention is:

1. A window unit for an oven door in a self-cleaning oven, comprising three glass panels disposed in spaced parallel relation, a continuous spacer between the inner and the middle panels, spacing means between the middle and the outer of said panels, a clamping frame adapted to clamp said panels against said spacer and spacing means and surrounding the peripheral edges of said panels, said middle panel being vertically movable relative to said outer panel, said outer and middle panels having strips of heat reflecting material thereon arranged in a pattern to define spaces therebetween for viewing into the oven when said middle panel is in a lower position, and to close said spaces to provide a heat reflecting shield over the entire area of said panels when said middle panel is in its upper position, thermally responsive means engageable with said middle panel to raise the same to said upper position when the oven temperature is above normal cooking temperatures, and resilient means urging said middle panel to said lower position.

2. A window unit according to claim 1 wherein said thermally responsive means comprise bimetallic strips confined between the lower edge of said middle panel and said clamping frame.

3. A window unit according to claim 2 wherein said resilient means comprise springs confined between the upper edge of said middle panel and said clamping frame.

4. A window unit according to claim 1 wherein said heat reflecting strips are secured on the inner side of said outer panel and the outer side of said middle panel.

5. A window unit for an oven door in a self-cleaning oven, comprising a pair of glass panels disposed in spaced parallel relation, spacing means between said panels, a clamping frame adapted to clamp said panels against said spacing means and surrounding the peripheral edges of said panels, one of said panels being vertically movable relative to the other panel, said panels having strips of heat reflective material thereon arranged in a pattern to define spaces therebetween for viewing into the oven when said one panel is in a lower position, and to close said spaces to provide a heat reflecting shield over the entire area of said panels when said one panel is in its upper position, and thermally responsive means engageable with said one panel to raise the same to said upper position when the oven temperature is above normal cooking temperatures.

6. A window unit according to claim 5 wherein said thermally responsive means comprise bimetallic strips confined between the lower edge of said one panel and said clamping frame.

7. A window unit according to claim 5 including springs confined between the upper edge of said one panel and said clamping frame to return said one panel to its lower position at temperatures within or below the cooking range.

8. A window unit according to claim 5 wherein said heat reflecting strips are secured on the opposing surfaces of said panels. 

1. A window unit for an oven door in a self-cleaning oven, comprising three glass panels disposed in spaced parallel relation, a continuous spacer between the inner and the middle panels, spacing means between the middle and the outer of said panels, a clamping frame adapted to clamp said panels against said spacer and spacing means and surrounding the peripheral edges of said panels, said middle panel being vertically movable relative to said outer panel, said outer and middle panels having strips of heat reflecting material thereon arranged in a pattern to define spaces therebetween for viewing into the oven when said middle panel is in a lower position, and to close said spaces to provide a heat reflecting shield over the entire area of said panels when said middle panel is in its upper position, thermally responsive means engageable with said middle panel to raise the same to said upper position when the oven temperature is above normal cooking temperatures, and resilient means urging said middle panel to said lower position.
 2. A window unit according to claim 1 wherein said thermally responsive means comprise bimetallic strips confined between the lower edge of said middle panel and said clamping frame.
 3. A window unit according to claim 2 wherein said resilient means comprise springs confined between the upper edge of said middle panel and said clamping frame.
 4. A window unit according to claim 1 wherein said heat reflecting strips are secured on the inner side of Said outer panel and the outer side of said middle panel.
 5. A window unit for an oven door in a self-cleaning oven, comprising a pair of glass panels disposed in spaced parallel relation, spacing means between said panels, a clamping frame adapted to clamp said panels against said spacing means and surrounding the peripheral edges of said panels, one of said panels being vertically movable relative to the other panel, said panels having strips of heat reflective material thereon arranged in a pattern to define spaces therebetween for viewing into the oven when said one panel is in a lower position, and to close said spaces to provide a heat reflecting shield over the entire area of said panels when said one panel is in its upper position, and thermally responsive means engageable with said one panel to raise the same to said upper position when the oven temperature is above normal cooking temperatures.
 6. A window unit according to claim 5 wherein said thermally responsive means comprise bimetallic strips confined between the lower edge of said one panel and said clamping frame.
 7. A window unit according to claim 5 including springs confined between the upper edge of said one panel and said clamping frame to return said one panel to its lower position at temperatures within or below the cooking range.
 8. A window unit according to claim 5 wherein said heat reflecting strips are secured on the opposing surfaces of said panels. 